CVE-2018-8420

Microsoft Windows VBScript Class_Terminate MSXML6 Use-After-Free Remote Code Execution Vulnerability

Severity Score

8.8

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

A remote code execution vulnerability exists when the Microsoft XML Core Services MSXML parser processes user input, aka "MS XML Remote Code Execution Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.

Existe una vulnerabilidad de ejecución remota de código cuando el analizador Microsoft XML Core Services MSXML procesa las entradas de usuario. Esto también se conoce como "MS XML Remote Code Execution Vulnerability". Esto afecta a Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10 y Windows 10 Servers.

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Windows VBScript. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the handling of Class_Terminate methods when used together with MSXML6. By performing actions in VBScript, an attacker can cause a pointer to be reused after it has been freed. An attacker can leverage this vulnerability to execute code in the context of the current process.

*Credits: Simon Zuckerbraun of Trend Micro Zero Day Initiative

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2018-03-14 CVE Reserved
2018-09-12 First Exploit
2018-09-13 CVE Published
2024-08-05 CVE Updated
2024-12-17 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-611: Improper Restriction of XML External Entity Reference

CAPEC

References (4)

URL	Tag	Source
http://www.securityfocus.com/bid/105259	Third Party Advisory
http://www.securitytracker.com/id/1041627	Third Party Advisory

URL	Date	SRC
https://github.com/idkwim/CVE-2018-8420	2018-09-12

URL	Date	SRC
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8420	2018-11-19

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Microsoft Search vendor "Microsoft"		Windows 10 Search vendor "Microsoft" for product "Windows 10"				-		-		Affected
Microsoft Search vendor "Microsoft"		Windows 10 Search vendor "Microsoft" for product "Windows 10"				1607 Search vendor "Microsoft" for product "Windows 10" and version "1607"		-		Affected
Microsoft Search vendor "Microsoft"		Windows 10 Search vendor "Microsoft" for product "Windows 10"				1703 Search vendor "Microsoft" for product "Windows 10" and version "1703"		-		Affected
Microsoft Search vendor "Microsoft"		Windows 10 Search vendor "Microsoft" for product "Windows 10"				1709 Search vendor "Microsoft" for product "Windows 10" and version "1709"		-		Affected
Microsoft Search vendor "Microsoft"		Windows 10 Search vendor "Microsoft" for product "Windows 10"				1803 Search vendor "Microsoft" for product "Windows 10" and version "1803"		-		Affected
Microsoft Search vendor "Microsoft"		Windows 7 Search vendor "Microsoft" for product "Windows 7"				-		sp1		Affected
Microsoft Search vendor "Microsoft"		Windows 8.1 Search vendor "Microsoft" for product "Windows 8.1"				-		-		Affected
Microsoft Search vendor "Microsoft"		Windows 8.1 Search vendor "Microsoft" for product "Windows 8.1"				-		rt		Affected
Microsoft Search vendor "Microsoft"		Windows Server Search vendor "Microsoft" for product "Windows Server"				2008 Search vendor "Microsoft" for product "Windows Server" and version "2008"		r2, sp1, itanium		Affected
Microsoft Search vendor "Microsoft"		Windows Server Search vendor "Microsoft" for product "Windows Server"				2008 Search vendor "Microsoft" for product "Windows Server" and version "2008"		r2, sp1, x64		Affected
Microsoft Search vendor "Microsoft"		Windows Server Search vendor "Microsoft" for product "Windows Server"				2008 Search vendor "Microsoft" for product "Windows Server" and version "2008"		sp2		Affected
Microsoft Search vendor "Microsoft"		Windows Server Search vendor "Microsoft" for product "Windows Server"				2012 Search vendor "Microsoft" for product "Windows Server" and version "2012"		-		Affected
Microsoft Search vendor "Microsoft"		Windows Server Search vendor "Microsoft" for product "Windows Server"				2012 Search vendor "Microsoft" for product "Windows Server" and version "2012"		r2		Affected
Microsoft Search vendor "Microsoft"		Windows Server Search vendor "Microsoft" for product "Windows Server"				2016 Search vendor "Microsoft" for product "Windows Server" and version "2016"		-		Affected
Microsoft Search vendor "Microsoft"		Windows Server Search vendor "Microsoft" for product "Windows Server"				2016 Search vendor "Microsoft" for product "Windows Server" and version "2016"		1709		Affected
Microsoft Search vendor "Microsoft"		Windows Server Search vendor "Microsoft" for product "Windows Server"				2016 Search vendor "Microsoft" for product "Windows Server" and version "2016"		1803		Affected